Various filtration devices have been developed which separate fluid constituents from each other or which separate fragments of fluid constituents from a fluid sample for recovery and analysis. For example, U.S. Pat. No. 5,846,493 to Bankier et al. describes a filtration system which utilizes a vacuum to draw a solution through a fibrous web filter to separate DNA particles from the solution. U.S. Pat. No. 4,948,564 to Root et al. and U.S. Pat. No. 5,141,719 to Fernwood et al. disclose filtration systems which utilize centrifugation, gravity, or vacuum to filter fluid samples through a microporous membrane filter. U.S. Pat. No. 5,160,704 to Schluter describes a serum separator which comprises a filter of vertically aligned fibers of absorbent material covered by a layer of dense acetate fabric. When the cell particle separator is lowered into a fluid sample, capillary action in the aligned fibers draws fluid into the filter, capturing larger particles which cannot be drawn into the filter against the layer of dense acetate fabric.
Some known filtration devices can be used in DNA filtration projects to filter samples containing DNA particles for recovery of genetic structures. However, known filters used in DNA retrieval systems typically provide a DNA particle recovery rate of 80% or less, and require substantial sample volumes (i.e., 100 microliters or more) to produce significant extraction volumes. Given that a year's development may be needed to produce even very small amounts (on the order of a few picograms) of fluid containing the desired DNA particles, the loss of DNA material due to inefficiencies in filtration and the inability to divide fluid portions into smaller sample volumes to produce more extractions are significant disadvantages.
Accordingly, it is a primary object of the current invention to provide a filtration apparatus which optimizes particle recovery from fluid samples.
A further object of the current invention is to provide a filtration system which can filter particles from sample fluid volumes of 50 microliters or less.
Another object of the current invention is to provide a filtration system which allows for the simultaneous filtration of numerous samples.
Other objects and advantages of the current invention will become apparent when the inventive filtration system is considered in conjunction with the accompanying drawings, specification, and claims.